Polarized magnet.



E. A. BURLINGAME.

POLARIZED MAGNET.

APPLICATION FILED MAY 11, 1908.

Patented July 20, 1909.

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ELMER BURLINGAME, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOB TO BURLINGAME TELEGRAPHING TYPEWRITER COMPANY, A CORPORATION OF WASHINGTON.

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Specification of Letters Patent.

Patented July 20, 1909.

Application filed Kay 11, 1908. Serial No. 482,280.

To all whom it may concern:

Be it known that I, ELMER A. BURLIN- GAME, a citizen of the United States, residing at San Francisco, California, have invented certain new and useful Improvements in Polarized Magnets, of which. the following is a s ecification.

y present invention relates to improvements in polarized magnets, and the object of the invention is to rovide an electroma etic device by which a part to be operate may be moved in either direction from a neutral position, according to the direction of the current traversing the magnet coils, and may be moved to distances varying according to the strength of current.

I have aimed to provide an extremely simple form of magnet in which magnetic resistance will be reduced to a minimum and which will operate efiiciently and reliably and may be produced at a low cost.

The invention includes the features of construction and arrangement and combination of arts hereinafter described and particular y set forth in the pended claims.

A magnet constructe in accordance with my invention is illustrated in the accompanyin drawing in which the figure represents a si e elevation of the magnet.

Referrin by reference characters to this drawing, I ave shown at 1 and 2, two ermanent bar ma nets, each of which is pre erably composed o a lurality of plates as shown. These car at their upper ends inwardly extending sdfl; iron pole pieces 3 and 4, the one of which should be positive and the other negative as indicated by the plus and minus signs, and are secured at their lower ends to the opposite sides of a soft iron bar or con ling member 5, the connection between t e bar magnets 1 and 2 and the ole and base being conveniently effected by means of screws as shown. The pole pieces, bar magnets and base as thus constructed constitute a horse shoe magnet. Mounted on the base piece 5 is a wire wound bobbin 6 having a soft iron core connected with said base and having a soft iron cap 7 at its end.

Above the cap 7 is located anarmature 8, which is supported by two arms.9, having their upper ends secured to the armature in any sultable manner as by screws 9*, and their lower ends ivotally connected'to the opposite sides of t e base piece 5 in any suita e manner as by screws 10.

-' I have found that when the widtli of the armature'is a little less than the air gap between the pole pieces 3 and 4, the magnetic action is stronger than if it bears any other ratio. I therefore make the armature of such dimensions and curve its upper surface on the arc of a circle concentric w1th the axis of the ivot screw 10. Its lower surface is similari y curved as also is the upper surface of the cap piece 7 and the under surfaces of the pole pleces 3 and 4. The distance between the concentric surfaces of the pole pieces 3 and 4 and the cap 7 are such thatwhen the arms 9 are swung to one side as indicated for instance in dotted lines in the figure under the impulse of a current the armature travels between the pole 3 and the cap 7 and with the least amount of clearance consistent with the free motion of the armature, thus reducing the magnetic resistance to a minimum.

In operation, the current flowing in'one direction through the coils of the magnet makes the end of the cap 7 for example, negative. Its polarit is assumed also by the armature 8 and t e armature is therefore re elled by the negative pole 4 and attracte by the positive pole 3, which-results.

in a movement of the armature 8 toward the pole 8. Similarly, when the ca 7 and armature 8 are magnetized positive y, the armature 8 will be moved to the right. I have shown at 11 a member projectlng from the armature which will serve as a convenient means of connecting the armature to the part to be 0 erated.

Havmg thus described my invention what I claim is 1. In combination, a ermanent horse shoe magnet havin suitab y shaped poles, a single magnet coil ocated within said horse shoe magnet and having a suitable soft iron core arranged substantlally parallel to the sides of the horse shoe ma net, and an arma-. ture movably supported between said core and poles.

2. In combination, a permanent horse shoe magnet having suitably shaped poles, a magnet coil located within said horse shoe magnet and having a suitable core, an armature located between the core, and poles, and arms pivotally connecting said armature with the base of the horse shoe magnet.

3. In combination, a permanent horse shoe magnet having suitably shaped poles, a mag- 'net coil located within the magnet and havlng a suitable core, an armature located between the poles and end of the core, arms connected to the said armature at one end and pivotally connected to the base of the magnet at the other end, the under surface of the poles and the upper and lower-surfaces of the armature being curved on arcs of circles concentric with the axis of the pivoted 10 arms, and the core having a part in proximity to the under surfaces of the armature also curved on the are of a circle concentric with the pivotal axis of the arms.

In testimony whereof,. I afiix my signa ture in presence of two witnesses.

ELMER A. BURLINGAME.

Witnesses JAMES M. SPEAR, Enw. L. TOLSON. 

